X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;ds=sidebyside;f=kernel%2Fkprobes.c;h=282035f3ae964e1e288f352c370be8edd11d3078;hb=7d47618a2ade0cb6d8a0b2597029c383c1662fa0;hp=612af2d616141b35beb410a5adc58a9be5fecd5b;hpb=afd66255b9a48f5851326ddae50e2203fbf71dc9;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 612af2d..282035f 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -42,6 +42,7 @@ #include #include #include +#include #include #include #include @@ -258,7 +259,8 @@ static void __kprobes __free_insn_slot(struct kprobe_insn_cache *c, struct kprobe_insn_page *kip; list_for_each_entry(kip, &c->pages, list) { - long idx = ((long)slot - (long)kip->insns) / c->insn_size; + long idx = ((long)slot - (long)kip->insns) / + (c->insn_size * sizeof(kprobe_opcode_t)); if (idx >= 0 && idx < slots_per_page(c)) { WARN_ON(kip->slot_used[idx] != SLOT_USED); if (dirty) { @@ -360,6 +362,9 @@ static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p) } #ifdef CONFIG_OPTPROBES +/* NOTE: change this value only with kprobe_mutex held */ +static bool kprobes_allow_optimization; + /* * Call all pre_handler on the list, but ignores its return value. * This must be called from arch-dep optimized caller. @@ -428,7 +433,7 @@ static __kprobes void kprobe_optimizer(struct work_struct *work) /* Lock modules while optimizing kprobes */ mutex_lock(&module_mutex); mutex_lock(&kprobe_mutex); - if (kprobes_all_disarmed) + if (kprobes_all_disarmed || !kprobes_allow_optimization) goto end; /* @@ -471,7 +476,7 @@ static __kprobes void optimize_kprobe(struct kprobe *p) struct optimized_kprobe *op; /* Check if the kprobe is disabled or not ready for optimization. */ - if (!kprobe_optready(p) || + if (!kprobe_optready(p) || !kprobes_allow_optimization || (kprobe_disabled(p) || kprobes_all_disarmed)) return; @@ -588,6 +593,80 @@ static __kprobes void try_to_optimize_kprobe(struct kprobe *p) optimize_kprobe(ap); } +#ifdef CONFIG_SYSCTL +static void __kprobes optimize_all_kprobes(void) +{ + struct hlist_head *head; + struct hlist_node *node; + struct kprobe *p; + unsigned int i; + + /* If optimization is already allowed, just return */ + if (kprobes_allow_optimization) + return; + + kprobes_allow_optimization = true; + mutex_lock(&text_mutex); + for (i = 0; i < KPROBE_TABLE_SIZE; i++) { + head = &kprobe_table[i]; + hlist_for_each_entry_rcu(p, node, head, hlist) + if (!kprobe_disabled(p)) + optimize_kprobe(p); + } + mutex_unlock(&text_mutex); + printk(KERN_INFO "Kprobes globally optimized\n"); +} + +static void __kprobes unoptimize_all_kprobes(void) +{ + struct hlist_head *head; + struct hlist_node *node; + struct kprobe *p; + unsigned int i; + + /* If optimization is already prohibited, just return */ + if (!kprobes_allow_optimization) + return; + + kprobes_allow_optimization = false; + printk(KERN_INFO "Kprobes globally unoptimized\n"); + get_online_cpus(); /* For avoiding text_mutex deadlock */ + mutex_lock(&text_mutex); + for (i = 0; i < KPROBE_TABLE_SIZE; i++) { + head = &kprobe_table[i]; + hlist_for_each_entry_rcu(p, node, head, hlist) { + if (!kprobe_disabled(p)) + unoptimize_kprobe(p); + } + } + + mutex_unlock(&text_mutex); + put_online_cpus(); + /* Allow all currently running kprobes to complete */ + synchronize_sched(); +} + +int sysctl_kprobes_optimization; +int proc_kprobes_optimization_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, + loff_t *ppos) +{ + int ret; + + mutex_lock(&kprobe_mutex); + sysctl_kprobes_optimization = kprobes_allow_optimization ? 1 : 0; + ret = proc_dointvec_minmax(table, write, buffer, length, ppos); + + if (sysctl_kprobes_optimization) + optimize_all_kprobes(); + else + unoptimize_all_kprobes(); + mutex_unlock(&kprobe_mutex); + + return ret; +} +#endif /* CONFIG_SYSCTL */ + static void __kprobes __arm_kprobe(struct kprobe *p) { struct kprobe *old_p; @@ -1509,6 +1588,72 @@ static void __kprobes kill_kprobe(struct kprobe *p) arch_remove_kprobe(p); } +/* Disable one kprobe */ +int __kprobes disable_kprobe(struct kprobe *kp) +{ + int ret = 0; + struct kprobe *p; + + mutex_lock(&kprobe_mutex); + + /* Check whether specified probe is valid. */ + p = __get_valid_kprobe(kp); + if (unlikely(p == NULL)) { + ret = -EINVAL; + goto out; + } + + /* If the probe is already disabled (or gone), just return */ + if (kprobe_disabled(kp)) + goto out; + + kp->flags |= KPROBE_FLAG_DISABLED; + if (p != kp) + /* When kp != p, p is always enabled. */ + try_to_disable_aggr_kprobe(p); + + if (!kprobes_all_disarmed && kprobe_disabled(p)) + disarm_kprobe(p); +out: + mutex_unlock(&kprobe_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(disable_kprobe); + +/* Enable one kprobe */ +int __kprobes enable_kprobe(struct kprobe *kp) +{ + int ret = 0; + struct kprobe *p; + + mutex_lock(&kprobe_mutex); + + /* Check whether specified probe is valid. */ + p = __get_valid_kprobe(kp); + if (unlikely(p == NULL)) { + ret = -EINVAL; + goto out; + } + + if (kprobe_gone(kp)) { + /* This kprobe has gone, we couldn't enable it. */ + ret = -EINVAL; + goto out; + } + + if (p != kp) + kp->flags &= ~KPROBE_FLAG_DISABLED; + + if (!kprobes_all_disarmed && kprobe_disabled(p)) { + p->flags &= ~KPROBE_FLAG_DISABLED; + arm_kprobe(p); + } +out: + mutex_unlock(&kprobe_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(enable_kprobe); + void __kprobes dump_kprobe(struct kprobe *kp) { printk(KERN_WARNING "Dumping kprobe:\n"); @@ -1610,10 +1755,14 @@ static int __init init_kprobes(void) } } -#if defined(CONFIG_OPTPROBES) && defined(__ARCH_WANT_KPROBES_INSN_SLOT) +#if defined(CONFIG_OPTPROBES) +#if defined(__ARCH_WANT_KPROBES_INSN_SLOT) /* Init kprobe_optinsn_slots */ kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; #endif + /* By default, kprobes can be optimized */ + kprobes_allow_optimization = true; +#endif /* By default, kprobes are armed */ kprobes_all_disarmed = false; @@ -1722,72 +1871,6 @@ static const struct file_operations debugfs_kprobes_operations = { .release = seq_release, }; -/* Disable one kprobe */ -int __kprobes disable_kprobe(struct kprobe *kp) -{ - int ret = 0; - struct kprobe *p; - - mutex_lock(&kprobe_mutex); - - /* Check whether specified probe is valid. */ - p = __get_valid_kprobe(kp); - if (unlikely(p == NULL)) { - ret = -EINVAL; - goto out; - } - - /* If the probe is already disabled (or gone), just return */ - if (kprobe_disabled(kp)) - goto out; - - kp->flags |= KPROBE_FLAG_DISABLED; - if (p != kp) - /* When kp != p, p is always enabled. */ - try_to_disable_aggr_kprobe(p); - - if (!kprobes_all_disarmed && kprobe_disabled(p)) - disarm_kprobe(p); -out: - mutex_unlock(&kprobe_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(disable_kprobe); - -/* Enable one kprobe */ -int __kprobes enable_kprobe(struct kprobe *kp) -{ - int ret = 0; - struct kprobe *p; - - mutex_lock(&kprobe_mutex); - - /* Check whether specified probe is valid. */ - p = __get_valid_kprobe(kp); - if (unlikely(p == NULL)) { - ret = -EINVAL; - goto out; - } - - if (kprobe_gone(kp)) { - /* This kprobe has gone, we couldn't enable it. */ - ret = -EINVAL; - goto out; - } - - if (p != kp) - kp->flags &= ~KPROBE_FLAG_DISABLED; - - if (!kprobes_all_disarmed && kprobe_disabled(p)) { - p->flags &= ~KPROBE_FLAG_DISABLED; - arm_kprobe(p); - } -out: - mutex_unlock(&kprobe_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(enable_kprobe); - static void __kprobes arm_all_kprobes(void) { struct hlist_head *head;